Timing issues

[curse]

I have a gm crate motor in my 79 c10. When I set the timing and it runs nice and smooth it cranks over really slow and don't start, I figure too advanced (if I remember, at this setting it is at about 2 dbtdc). So I set it at 12 dbtdc and it turns over and starts easy but runs rough like the timing is off. Would being off a tooth cause this or would problem still exist if I pulled distributor and moved it a tooth or possible issue with distributor? New plugs, wires, cap, rotor, and coil.

 

[Jethro224]

Being off a tooth shouldn't cause the problem.
Sounds like something else going on. I would guess maybe stuck advance weights. More info needed.

 

[75gmck25]

8-12 degrees BTDC is usually about right, and you want about 18-20 degrees more from the mechanical advance. Total advance with no vacuum canister connected should be no higher than about 34-36. Most vacuum canisters will add about 18-20 degrees.

It may tolerate up to 16 degrees initial, but you have to listen for pinging under light load and back it off a little if needed. Stock mechanical advance usually comes in fairly late (3k rpm), but acceleration will improve if you can adjust it (use an adjustable advance kit) and get full mechanical by about 2000-2500 rpm.

 

[curse]

advance weights were stuck, I had to turn the rotor with a good amount of force to get the weights to move. Now they move but do not return on there own. This distributor has good reviews but it it says it will not fit my 79 c10 with a 350....why wouldn't it?

Amazon.com: Performance Hei Ignition Distributor Compatible with Chevy GM SBC BBC 9000RPM V8 65k Coil 283 305 307 327 350 400 Small Blocks and 396 427 454 Big Blocks: Automotive

 

[75gmck25]

Are you reading that goofy table at the end of their product description? It makes no sense, since the year range for each vehicle ends in 1973, but GM didn’t make HEI standard until 1975 in trucks. Based on the rest of their info, it should work fine for your 1979 truck with a 350. Just call or email them to confirm.

 

[curse]

I didn't see that but went back and read it. That is goofy.